Can someone recommend either a web based program that already does this, or which language would be the best to write it in.

Client logs into the secure web site to update selected allowed information, this then can download into the application that is on the computer that will load it to the card.

Admin’s log into the secure web site to update information, this can then be downloaded into the application that is on the computer that will load it to the card.

You would need me to write the online programming that would contain the log in page, the database that it connects to to verify the user id and password, the interface (page) that the clients and admin would use to input information, (the database that contains all the info selected to the appropriate user name, and the download link that would create the info in the correct file to import into the standalone app?

Database, web login, ... I think PHP is most suitable for this kind of job

Thank you for the advice. At least you choose to help instead of treating someone like an idiot.

Do you know of any prewritten ones?

no, not really. Try google, you might find something.